{"id":247345,"date":"2024-01-02T20:47:24","date_gmt":"2024-01-02T12:47:24","guid":{"rendered":"https:\/\/www.idc.net\/help\/247345\/"},"modified":"2024-01-02T20:47:24","modified_gmt":"2024-01-02T12:47:24","slug":"mongodb-%e6%9c%af%e8%af%ad-%e6%b8%b8%e6%a0%87","status":"publish","type":"post","link":"https:\/\/idc.net\/help\/247345\/","title":{"rendered":"MongoDB \u672f\u8bed &#8211; \u6e38\u6807"},"content":{"rendered":"<p><title>MongoDB \u672f\u8bed - \u6e38\u6807<\/title><\/p>\n<h1 id=\"mongodb-%e6%9c%af%e8%af%ad-%e6%b8%b8%e6%a0%87-HAsXZxyHEE\"> MongoDB \u672f\u8bed - \u6e38\u6807 <\/h1>\n<p>\u5728MongoDB\u4e2d\uff0c\u6e38\u6807\uff08Cursor\uff09\u662f\u4e00\u79cd\u7528\u4e8e\u4ece\u67e5\u8be2\u7ed3\u679c\u96c6\u4e2d\u83b7\u53d6\u6570\u636e\u7684\u673a\u5236\u3002\u5f53\u6267\u884c\u67e5\u8be2\u65f6\uff0cMongoDB\u4f1a\u8fd4\u56de\u4e00\u4e2a\u6e38\u6807\u5bf9\u8c61\uff0c\u8be5\u5bf9\u8c61\u53ef\u4ee5\u7528\u4e8e\u9010\u4e2a\u83b7\u53d6\u67e5\u8be2\u7ed3\u679c\u4e2d\u7684\u6587\u6863\u3002<\/p>\n<h2 id=\"%e6%b8%b8%e6%a0%87%e7%9a%84%e5%9f%ba%e6%9c%ac%e7%94%a8%e6%b3%95-HAsXZxyHEE\"> \u6e38\u6807\u7684\u57fa\u672c\u7528\u6cd5 <\/h2>\n<p>\u8981\u4f7f\u7528\u6e38\u6807\uff0c\u9996\u5148\u9700\u8981\u6267\u884c\u4e00\u4e2a\u67e5\u8be2\u64cd\u4f5c\u3002\u67e5\u8be2\u64cd\u4f5c\u53ef\u4ee5\u4f7f\u7528find()\u65b9\u6cd5\u6765\u6267\u884c\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre><code>db.collection.find(query, projection)<\/code><\/pre>\n<p>\u5176\u4e2d\uff0c<code>query<\/code>\u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u67e5\u8be2\u6761\u4ef6\uff0c<code>projection<\/code>\u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u8fd4\u56de\u7684\u5b57\u6bb5\u3002<\/p>\n<p>\u6267\u884c\u67e5\u8be2\u540e\uff0c\u53ef\u4ee5\u901a\u8fc7\u8c03\u7528\u6e38\u6807\u5bf9\u8c61\u7684<code>next()<\/code>\u65b9\u6cd5\u6765\u83b7\u53d6\u4e0b\u4e00\u4e2a\u6587\u6863\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>var cursor = db.collection.find();\nwhile (cursor.hasNext()) {\n    var document = cursor.next();\n    \/\/ \u5904\u7406\u6587\u6863\n}<\/code><\/pre>\n<p>\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c<code>cursor.hasNext()<\/code>\u65b9\u6cd5\u7528\u4e8e\u5224\u65ad\u6e38\u6807\u662f\u5426\u8fd8\u6709\u4e0b\u4e00\u4e2a\u6587\u6863\uff0c\u5982\u679c\u6709\uff0c\u5219\u8c03\u7528<code>cursor.next()<\/code>\u65b9\u6cd5\u83b7\u53d6\u4e0b\u4e00\u4e2a\u6587\u6863\u3002<\/p>\n<h2 id=\"%e6%b8%b8%e6%a0%87%e7%9a%84%e5%b8%b8%e7%94%a8%e6%96%b9%e6%b3%95-HAsXZxyHEE\"> \u6e38\u6807\u7684\u5e38\u7528\u65b9\u6cd5 <\/h2>\n<p>\u9664\u4e86<code>next()<\/code>\u65b9\u6cd5\u5916\uff0c\u6e38\u6807\u8fd8\u63d0\u4f9b\u4e86\u5176\u4ed6\u4e00\u4e9b\u5e38\u7528\u7684\u65b9\u6cd5\uff0c\u7528\u4e8e\u65b9\u4fbf\u5730\u64cd\u4f5c\u67e5\u8be2\u7ed3\u679c\u96c6\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u7684\u6e38\u6807\u65b9\u6cd5\uff1a<\/p>\n<ul>\n<li><code>limit(n)<\/code>\uff1a\u9650\u5236\u67e5\u8be2\u7ed3\u679c\u8fd4\u56de\u7684\u6587\u6863\u6570\u91cf\u4e3a<code>n<\/code>\u3002<\/li>\n<li><code>skip(n)<\/code>\uff1a\u8df3\u8fc7\u524d<code>n<\/code>\u4e2a\u6587\u6863\uff0c\u8fd4\u56de\u5269\u4e0b\u7684\u6587\u6863\u3002<\/li>\n<li><code>sort(keys)<\/code>\uff1a\u6309\u7167\u6307\u5b9a\u7684\u952e\u5bf9\u67e5\u8be2\u7ed3\u679c\u8fdb\u884c\u6392\u5e8f\u3002<\/li>\n<li><code>count()<\/code>\uff1a\u8fd4\u56de\u67e5\u8be2\u7ed3\u679c\u7684\u6587\u6863\u6570\u91cf\u3002<\/li>\n<\/ul>\n<p>\u8fd9\u4e9b\u65b9\u6cd5\u53ef\u4ee5\u5728\u6267\u884c\u67e5\u8be2\u4e4b\u540e\uff0c\u901a\u8fc7\u8c03\u7528\u6e38\u6807\u5bf9\u8c61\u7684\u65b9\u5f0f\u6765\u4f7f\u7528\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>var cursor = db.collection.find().limit(10).skip(5).sort({name: 1});\nwhile (cursor.hasNext()) {\n    var document = cursor.next();\n    \/\/ \u5904\u7406\u6587\u6863\n}<\/code><\/pre>\n<p>\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c<code>limit(10)<\/code>\u65b9\u6cd5\u9650\u5236\u8fd4\u56de\u7684\u6587\u6863\u6570\u91cf\u4e3a10\uff0c<code>skip(5)<\/code>\u65b9\u6cd5\u8df3\u8fc7\u524d5\u4e2a\u6587\u6863\uff0c<code>sort({name: 1})<\/code>\u65b9\u6cd5\u6309\u7167<code>name<\/code>\u5b57\u6bb5\u8fdb\u884c\u5347\u5e8f\u6392\u5e8f\u3002<\/p>\n<h2 id=\"%e6%b8%b8%e6%a0%87%e7%9a%84%e6%80%a7%e8%83%bd%e8%80%83%e8%99%91-HAsXZxyHEE\"> \u6e38\u6807\u7684\u6027\u80fd\u8003\u8651 <\/h2>\n<p>\u5728\u4f7f\u7528\u6e38\u6807\u65f6\uff0c\u9700\u8981\u6ce8\u610f\u4e00\u4e9b\u6027\u80fd\u65b9\u9762\u7684\u8003\u8651\u3002\u5982\u679c\u67e5\u8be2\u7ed3\u679c\u96c6\u975e\u5e38\u5927\uff0c\u4e00\u6b21\u6027\u83b7\u53d6\u6240\u6709\u6587\u6863\u53ef\u80fd\u4f1a\u5bfc\u81f4\u5185\u5b58\u4e0d\u8db3\u7684\u95ee\u9898\u3002\u56e0\u6b64\uff0c\u53ef\u4ee5\u901a\u8fc7\u9002\u5f53\u5730\u4f7f\u7528<code>limit()<\/code>\u548c<code>skip()<\/code>\u65b9\u6cd5\u6765\u5206\u6279\u83b7\u53d6\u6587\u6863\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u5982\u679c\u67e5\u8be2\u7ed3\u679c\u96c6\u9700\u8981\u6309\u7167\u67d0\u4e2a\u5b57\u6bb5\u8fdb\u884c\u6392\u5e8f\uff0c\u53ef\u4ee5\u8003\u8651\u5728\u8be5\u5b57\u6bb5\u4e0a\u521b\u5efa\u7d22\u5f15\uff0c\u4ee5\u63d0\u9ad8\u67e5\u8be2\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e6%80%bb%e7%bb%93-HAsXZxyHEE\"> \u603b\u7ed3 <\/h2>\n<p>\u6e38\u6807\u662fMongoDB\u4e2d\u7528\u4e8e\u83b7\u53d6\u67e5\u8be2\u7ed3\u679c\u7684\u673a\u5236\u3002\u901a\u8fc7\u6e38\u6807\uff0c\u53ef\u4ee5\u9010\u4e2a\u83b7\u53d6\u67e5\u8be2\u7ed3\u679c\u4e2d\u7684\u6587\u6863\uff0c\u5e76\u8fdb\u884c\u76f8\u5e94\u7684\u5904\u7406\u3002\u5728\u4f7f\u7528\u6e38\u6807\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528<code>limit()<\/code>\u3001<code>skip()<\/code>\u3001<code>sort()<\/code>\u7b49\u65b9\u6cd5\u6765\u65b9\u4fbf\u5730\u64cd\u4f5c\u67e5\u8be2\u7ed3\u679c\u96c6\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5728\u5904\u7406\u5927\u91cf\u6587\u6863\u65f6\uff0c\u5e94\u8be5\u8003\u8651\u5206\u6279\u83b7\u53d6\u6587\u6863\u4ee5\u53ca\u521b\u5efa\u7d22\u5f15\u6765\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n<h3 id=\"%e9%a6%99%e6%b8%af%e6%9c%8d%e5%8a%a1%e5%99%a8%e9%a6%96%e9%80%89%e5%90%8e%e6%b5%aa%e4%ba%91-HAsXZxyHEE\"> \u9999\u6e2f\u670d\u52a1\u5668\u9996\u9009\u540e\u6d6a\u4e91 <\/h3>\n<p>\u540e\u6d6a\u4e91\u662f\u4e00\u5bb6\u4e13\u4e1a\u7684\u4e91\u8ba1\u7b97\u516c\u53f8\uff0c\u63d0\u4f9b\u9ad8\u6027\u80fd\u7684\u9999\u6e2f\u670d\u52a1\u5668\u3002\u4f5c\u4e3a\u9999\u6e2f\u670d\u52a1\u5668\u7684\u9996\u9009\u54c1\u724c\uff0c\u540e\u6d6a\u4e91\u81f4\u529b\u4e8e\u4e3a\u7528\u6237\u63d0\u4f9b\u7a33\u5b9a\u53ef\u9760\u7684\u670d\u52a1\u5668\u89e3\u51b3\u65b9\u6848\u3002\u5982\u679c\u60a8\u9700\u8981\u9999\u6e2f\u670d\u52a1\u5668\uff0c\u53ef\u4ee5\u8bbf\u95ee<a href=\"https:\/\/idc.net\">\u540e\u6d6a\u4e91\u5b98\u7f51<\/a>\u4e86\u89e3\u66f4\u591a\u4fe1\u606f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>MongoDB \u672f\u8bed - \u6e38\u6807 MongoDB \u672f\u8bed - \u6e38\u6807 \u5728MongoDB\u4e2d\uff0c\u6e38\u6807\uff08Cursor\uff09\u662f\u4e00\u79cd [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7038],"tags":[],"class_list":["post-247345","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/247345","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/comments?post=247345"}],"version-history":[{"count":0,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/247345\/revisions"}],"wp:attachment":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media?parent=247345"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/categories?post=247345"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/tags?post=247345"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}